Pinch clamp devices are well known and have been used successfully for many years in the medical field and in research laboratories for regulating by a simple one-hand operating action the flow of fluids in flexible tubing, particularly to and from patients. Pinch clamp devices are essentially flow control devices or clamps for use with a length of resilient collapsible tube or tubing, wherein fluid flow through the tube may be selectively enabled and stopped, and in some cases regulated, by means of a pair of opposed clamping abutments acting on the tube, without contact between the device and the fluid.
Most of these devices suffer from the disadvantage that the tubing has to be inserted into the clamping device in a longitudinal manner, i.e., the tube has to be threaded into the clamp endwise. Since this type of tubing generally comprises fixed end connectors and/or equipment and/or fixtures, and in fact commercially available tubing is rarely obtainable without such connectors, equipment and/or fixtures, it is not possible, nor in any event practical, to mount the device onto the tubing once the end connectors have been fixed, particularly when the tubing is connected to other equipment and/or the patient. Thus lengths of tubing comprising a clamping device mounted thereon are typically assembled and marketed as a set, which tends to be significantly more expensive than the sum of the cost of a clamp plus the cost of a similar set minus the clamp, thereby contributing to health care and insurance expenses. Furthermore, there are many instances where a simple tube with end connectors is required, or when only say one of the tubes in a bifurcated tube, for example, needs to be clamped, and as such similar tubes provided with a full complement of clamps are unnecessary and therefore add expense to the medical treatment being provided. The alternative of using a one-way stopcock, mounted on-site by professional medical staff when the tube does not comprise a clamp, is significantly expensive and also increases healthcare costs.
There are also applications where clamps are not generally pre-mounted onto tubing, as in the case, for example, of catheters. In such applications, it may nevertheless be advantageous to clamp the tube at some point prior to retrieving the tube from the body. For example, on site clamping can also prevent spillage of liquid contamination at the open ends of tubes, drains and catheters (pippet effect), such as in urology, gastric zonds, etc., when these are removed from a patient or when the vacuum system is closed. However, it is not possible to insert a conventional pinch clamp longitudinally onto the tube/drain/catheter, once inserted into the body. In such cases, the provision of a clamp which can be laterally mounted onto the pipe/drain/catheter would be considerably advantageous.
U.S. Pat. No. 4,588,160 to Flynn et al. and U.S. Pat. No. 3,942,228 to Buckman et al. each discloses a tube clamping device which includes a pair of arms with tube clamping means thereon which are movable from an open position to a latched, closed position in which the clamping means effects occlusion of a tube passing through the clamp. Each arm has a slot extending into the sidewall of the arm so that the tube can be laterally inserted and removed from the clamping device.
However, in both these references the lateral slot for laterally inserting the tube onto the device is closely correlated to the size of the tubing. Thus, the clamp cannot be used with larger diameter tubing, and furthermore, smaller diameter tubes would easily fall out of the clamp when in the unclamped position. As such, a potential user requires as many different sized clamps as he has different sized tubing, which is economically as well as logistically disadvantageous.
One aim of the present invention is to overcome the aforementioned disadvantages of the prior art pinch clamp devices.
It is another aim of the present invention to provide a pinch clamping device which may be laterally mounted onto a length of tubing.
In particular, it is an aim of the present invention to provide a pinch clamping device which may be mounted onto a piece of resilient tubing which comprises end connectors or which cannot be disconnected from other equipment.
It is also an aim of the present invention to provide a pinch clamping device which may be mounted onto a piece of resilient tubing which is indwelling in a body.
It is another aim of the present invention to provide a pinch clamping device which may be mounted onto a piece of resilient tubing which is indwelling in a body.
It is another aim of the present invention to provide a pinch clamping device which may be positively mounted onto resilient tubing and which is substantially prevented from accidentally coming off the tubing when in the unclamped position.
The present invention achieves these and other aims by providing a pinch clamping device comprising a pair of longitudinal arms with tube clamping means thereon which are movable from an open position to a latched, closed position in which the clamping means effects occlusion of a tube passing through the clamp. The pinch clamping device is characterized in that the clamping means project laterally from the arms, enabling a length of tubing to be laterally inserted into the device, in-between the clamping means such that with the tubing in place, the device may operate substantially in much the same way as regular prior art pinch clamp devices. The pinch clamping device is also characterized in comprising lateral guard means for preventing the device from being inadvertently or accidentally removed from the tubing, or from simply falling off the tubing, when in the unclamped position.
Thus, by providing a portion of the aligned clamping means laterally extending from the body of the clamp, rather than having slots cut into the clamp, the pinch clamping device is much more versatile than prior art clamps and may be laterally mounted onto tubing comprising a range of diameters. To further ensure that the clamp remains on the tubing even when the tubing is unclamped, and auxiliary catch member and latch means are provided, which when mutually engaged bring the lateral guard means into an overlapping relationship with the facing clamping means, thereby positively trapping the device onto the tubing.
The device of the present invention is thus robust, relatively inexpensive, easy to use, and typically requires a simple one-hand operation for installation onto tubing. After installation, the clamp is operated in much the same fashion as prior art pinch clamps, including the advantage that the clamp does not tend to fall off tubing when not being used.